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# Find the sum of N terms of the series 12, 14, 24, 58, 164, …

• Last Updated : 16 Aug, 2022

Given a positive integer, N. Find the sum of the first N term of the series 12, 14, 24, 58, 164, …..

Examples:

Input: N = 5
Output: 272

Input: N = 3
Output: 50

Approach:

The sequence is formed by using the following pattern. For any value N-

SN = 3N – N2 + 11 * N – 1

Illustration:

Input: N = 5
Output: 272
Explanation:
SN = 3N – N2 + 11 * N – 1
= 35 – 52 + 11 * 5 – 1
= 243 – 25 + 54
= 272

Below is the implementation of the above approach:

## C++

 `// C++ program to implement` `// the above approach` `#include ` `using` `namespace` `std;`   `// Function to return sum of` `// N term of the series` `int` `findSum(``int` `N)` `{` `    ``return` `(``pow``(3, N) - ` `            ``pow``(N, 2) + ` `            ``11 * N - 1);` `}`   `// Driver Code` `int` `main()` `{` `    ``int` `N = 5;` `    ``cout << findSum(N);` `    ``return` `0;` `}`

## Java

 `// Java program to implement` `// the above approach` `class` `GFG {`   `    ``// Function to return sum of` `    ``// N term of the series` `    ``static` `int` `findSum(``int` `N) {` `        ``return` `(``int``) (Math.pow(``3``, N) - Math.pow(N, ``2``) + ``11` `* N - ``1``);` `    ``}`   `    ``// Driver Code` `    ``public` `static` `void` `main(String args[]) {` `        ``int` `N = ``5``;` `        ``System.out.print(findSum(N));` `    ``}` `}`   `// This code is contributed by saurabh_jaiswal.`

## Python3

 `# Python code for the above approach`   `# Function to return sum of` `# N term of the series` `def` `findSum(N):` `    ``return` `((``3` `*``*` `N) ``-` `        ``(N ``*``*` `2``) ``+` `        ``11` `*` `N ``-` `1``);`   `# Driver Code`   `# Get the value of N` `N ``=` `5``;` `print``(findSum(N));`   `# This code is contributed by Saurabh Jaiswal`

## C#

 `// C# program to implement` `// the above approach` `using` `System;` `class` `GFG` `{`   `  ``// Function to return sum of` `    ``// N term of the series` `    ``static` `int` `findSum(``int` `N) {` `        ``return` `(``int``) (Math.Pow(3, N) - Math.Pow(N, 2) + 11 * N - 1);` `    ``}`   `  ``// Driver Code` `  ``public` `static` `void` `Main()` `  ``{` `    ``int` `N = 5;` `    ``Console.Write(findSum(N));`   `  ``}` `}`   `// This code is contributed by Samim Hossain Mondal.`

## Javascript

 ``

Output

`272`

Time Complexity: O(logN) since it is using pow function

Auxiliary Space: O(1), since no extra space has been taken.

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